package com.gosling.cloudspace.config;

import com.gosling.cloudspace.tools.IOTool;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

@SuppressWarnings("all")
@WebServlet(name = "VerifyCodeImage", urlPatterns = "/VerifyCodeImage", asyncSupported = true)
public class VerifyCodeImageServlet extends HttpServlet {
    public static final String VALIDATE_CODE = "validateCode";
    private static int WIDTH = 131;
    private static int HEIGHT = 50;

    static {
        System.setProperty("java.awt.headless", "true");
    }

    protected final Logger logger = LoggerFactory.getLogger(getClass());
//    @Autowired
//    RedisBaseServiceImpl redis;

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        ByteArrayOutputStream bos = null;
        ServletOutputStream sos = null;
        try {
            logger.info("开始生成验证码.....");
//            redis = Objects.isNull(redis) ? SpringBeanTool.getBean(RedisBaseServiceImpl.class) : redis;
            response.setContentType("static/image/jpeg");
            sos = response.getOutputStream();
            // 设置浏览器不要缓存此图片
            response.setHeader("Pragma", "No-cache");
            response.setHeader("Cache-Control", "no-cache");
            response.setDateHeader("Expires", 0);
            // 创建内存图象并获得其图形上下文
            BufferedImage image = new BufferedImage(WIDTH, HEIGHT,
                    BufferedImage.TYPE_INT_RGB);
            Graphics g = image.getGraphics();
            // 产生随机的认证码
            char[] rands = generateCheckCode();
            // 产生图像
            drawBackground(g);
            drawRands(g, rands);
            // 结束图像 的绘制 过程， 完成图像
            g.dispose();
            // 将图像输出到客户端
            bos = new ByteArrayOutputStream();
            ImageIO.write(image, "JPEG", bos);
            byte[] buf = bos.toByteArray();
            response.setContentLength(buf.length);
            // 下面的语句也可写成： bos.writeTo(sos);
            sos.write(buf);
            // 将当前验证码存入到 redis 中
//            redis.set(VALIDATE_CODE, new String(rands), 30);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            IOTool.closeQuietly(bos);
            IOTool.closeQuietly(sos);
        }
    }

    private char[] generateCheckCode() {
        // 定义验证码的字符表
        String chars = "2345678abcdefghjkmnprstuwxz";
        char[] rands = new char[4];
        for (int i = 0; i < 4; i++) {
            int rand = (int) (Math.random() * chars.length());
            rands[i] = chars.charAt(rand);
        }
        return rands;
    }

    /***
     * 在不同的高度上输出验证码的每个字符
     *
     * @param g
     * @param rands
     */
    private void drawRands(Graphics g, char[] rands) {
        g.setColor(Color.BLACK);
        g.setFont(new Font(null, Font.ITALIC | Font.BOLD, 26));
        // 在不同的高度上输出验证码的每个字符
        g.drawString("" + rands[0], 20, 37);
        g.drawString("" + rands[1], 40, 35);
        g.drawString("" + rands[2], 60, 38);
        g.drawString("" + rands[3], 80, 36);
    }

    /***
     * 产生干扰点、画背景图
     *
     * @param g
     */
    private void drawBackground(Graphics g) {
        // 画背景
        g.setColor(new Color(0xDCDCDC));
        g.fillRect(0, 0, WIDTH, HEIGHT);
        // 随机产生 120 个干扰点
        for (int i = 0; i < 120; i++) {
            int x = (int) (Math.random() * WIDTH);
            int y = (int) (Math.random() * HEIGHT);
            int red = (int) (Math.random() * 255);
            int green = (int) (Math.random() * 255);
            int blue = (int) (Math.random() * 255);
            g.setColor(new Color(red, green, blue));
            g.drawOval(x, y, 1, 0);
        }
    }
}
